Notes, summaries, assignments, exams, and problems for Geology

Fixism: A Rejected Theory

Fixism is a belief that maintains existing species have remained unchanged since their creation. It is rejected as an explanation for the origin of species because it cannot answer questions such as:

• The existence of huge variability among individuals of the same species.
• The existence of fossils.
• The presence of vestigial organs.
• The similarities in internal organs of species that are very different.
• The fact that an individual's ontogeny reflects its phylogeny.

Natural and Artificial Selection

Natural selection states that descendants survive whose changes pose an advantage in adapting to the environment, and they may transmit those changes to their descendants. Artificial selection is a process where humans select different... Continue reading "Understanding Biological Evolution: Fixism, Natural Selection, and Paleontology" »

Masterpieces of Classical Sculpture

Myron's Discobolus (The Discus Thrower)

Myron's Discobolus breaks with stiff archaic sculpture, introducing mobility and strain in the limbs and head, capturing a moment of athletic tension.

Polykleitos' Doryphoros (The Spear Bearer)

Polykleitos' Doryphoros established his famous canon, where the measure of the head is one-seventh of the whole body.

Praxiteles' Aphrodite of Knidos

The Aphrodite of Knidos, by Praxiteles, is depicted ready for swimming. Her serene and modest face reflects the aesthetic ideals of classical sculpture.

Ancient Wonders and Roman Engineering

Trajan's Column

The Trajan Column, 43 meters high, commemorates Emperor Trajan's victories against the Dacians (in modern Romania). The scenes, made... Continue reading "Masterpieces of Antiquity: Sculpture, Monuments, and Roman Architecture" »

Earth's Atmosphere

The atmosphere is the gaseous layer that surrounds the Earth. It is made up of nitrogen, oxygen, and 1% argon, CO2, neon, helium, ozone, dust, and water vapor.

• Troposphere: The layer in contact with the ground, between 10 and 11 km high. It is responsible for the greenhouse effect and meteorological phenomena. The temperature decreases with height.
• Stratosphere: Extends to 45 km altitude. Its temperature increases with height. The ozone layer, which absorbs ultraviolet radiation, is located here.
• Mesosphere: Extends to approximately 80 km in height. This is where meteorites falling to Earth become incandescent and turn into shooting stars.
• Thermosphere: This layer reaches 500 km in height and contains ionized gases.
• Exosphere:

What resources do we provide the forest? Explains their importance.

• Wood: It is the most important structural material from trees, composed of cellulose and lignin.
• Fuel: Low-grade wood is used for combustion.
• Cork and Resin: These are valuable materials derived from trees.
• Food: Forests provide foods like berries, mushrooms, and game animals.
• Fodder: Livestock feed is often sourced from forested areas.
• Medicinal Plants: Many plants found in forests have medicinal properties.

What do they have in common with agricultural resources and ranchers? Agricultural resources are exclusively the product of agricultural activity. This means the set of techniques and activities have the objective of cultivating land. Resources for farmers in livestock: This... Continue reading "Essential Resources Provided by Forests and Their Importance" »

Marxism

Marxism is a philosophy with a close relationship to science. Unlike speculative philosophies following the Platonic tradition, it is politically implemented. It is also a materialist philosophy, a dialectical materialism, which conceives matter not as inert and determined by mechanical laws, but as something dynamic and evolving, with its own internal contradictions as the driving force. Founded by Karl Marx, its study concerns the historical evolution of human societies, emphasizing historical materialism, which focuses on the various modes of production societies use to create their material existence. Historical development is linked to the ideologies and policies of socialism and communism. Its influence on the Frankfurt School... Continue reading "Understanding Marxism, Nihilism, Phenomenology, and Existentialism" »

Fundamental Earth Science Terminology

Map Scale

The relationship between a measured length on a map and the corresponding length in reality.

Topographical Map

A type of base map representing the physical and human aspects of an area, making them more prominent.

Solstice

A time in Earth's orbit when the Sun is perpendicular to the Tropics.

Equinox

A time in Earth's orbit when the Sun is perpendicular to the Equator.

Meseta

A very large, flat surface elevated above sea level.

Socket

Paleozoic platform rocks forming the basis of the relief.

Cordillera (or highlight skiing)

A high-elevation mountain range that emerged during the Tertiary Orogeny.

Sedimentary Basin (or depression)

A depressed zone formed during the Tertiary period and filled with sediments.

Relief

The Greenhouse Effect: A Natural Phenomenon

Climate warming is a natural process that the Earth undergoes. The atmosphere contains greenhouse gases (GHG) that are mainly water vapor (the largest contributor), carbon dioxide (CO₂), and methane (CH₄). This effect is analogous to a greenhouse used in gardening and agriculture.

Greenhouse Analogy Explained

In a greenhouse, a structure enclosed by glass or plastic allows sunlight to pass through, trapping heat inside and creating a micro-climate favorable for plant growth. This natural greenhouse effect is essential for maintaining habitable temperatures on Earth.

Human Influence and Rising Concentrations

However, human activities, particularly in recent decades, have significantly increased the concentration... Continue reading "Greenhouse Effect: Natural Process and Human Impact on Climate" »

Atlantic Spain (Euro-Siberian)

Characterized by wet weather and mild temperatures, this region is home to deciduous forests. These forests feature tall trees with large leaves, requiring ample water. While there are relatively few species, hardwood forests have large populations. In mountainous areas, coniferous forests dominate. The highest points of the Pyrenees and the Cantabrian mountain range feature alpine meadows, as the altitude and snow prevent tree growth.

Mediterranean Spain

This region endures arid months. It is characterized by evergreen forests with small trees, low branches, and sparse growth. Oaks are found in more humid areas, while scrubland dominates the driest places. It's important to note that pine forests are often a... Continue reading "Vegetation Zones in Spain: Atlantic, Mediterranean, Macaronesian" »

Earthquakes and Volcanoes

Earthquakes

An earthquake is a violent trembling of the Earth's crust, lasting a short time and varying in intensity. It occurs when materials abruptly fracture within the lithosphere. The point of origin is called the hypocenter. From the hypocenter, freed energy transmits as seismic waves in all directions. The most affected surface point is the epicenter. Energy transmits in superficial seismic waves.

Volcanoes

Volcanoes expel extremely hot materials. A volcano is an opening in the Earth's crust through which melted rocky materials from inside the Earth are expelled. This material is called magma within the crust and lava once expelled.

Continental Drift and Plate Tectonics

Continental Drift

Alfred Wegener proposed the... Continue reading "Earth's Dynamic Processes: Earthquakes, Volcanoes, and Plate Tectonics" »

Earth's Geological Features

Continental Landforms

Mountain Ranges: Formation & Tectonics

Mountain ranges form through a slow process, taking about 100 million years, which is impossible to appreciate during a human lifetime.

The interaction of two tectonic plates is key to understanding mountain ranges. Areas where two plates *collide* are subjected to immense pressure, compressing sediments deposited on the ocean floor and causing them to fold, thus forming mountains. This explains why *volcanic and seismic movements* are frequent in mountainous regions.

Ocean Floor Topography

Key Seafloor Features

• Mid-Ocean Ridges: These are large underwater *elevations* located in the central part of the oceans. They have an average height of 2,000 meters and